<template>
  <view>
    <my-search @click="goSearch"></my-search>
    <view class="scroll-view-container">
      <!-- 左侧的滚动视图区域 -->
      <scroll-view class="left-scroll-view" scroll-y :style="{height: wh+'px'}">
        <!-- 左侧的滚动视图区域 -->
        <scroll-view class="left-scroll-view" scroll-y :style="{height: wh + 'px'}">
          <block v-for="(item, i) in cateList" :key="i">
            <view :class="['left-scroll-view-item', i === active ? 'active' : '']" @click="activeChanged(i)">
              {{item.cat_name}}</view>
          </block>
        </scroll-view>
      </scroll-view>
 <!-- 右侧滑动区域 -->
 <scroll-view scroll-y="true" :style="{height:wh + 'px'}" :scroll-top="scrollTop">
   <!-- 二级分类 -->
   <view class="cate-lv2" v-for="(item2,i2) in cateLevel2" :key="i2">
     <!-- 二级分类标题 -->
     <view class="cate-lv2-title">
       /{{item2.cat_name}}/
     </view>
     <!-- 当前二级分类下的三级列表 -->
     <view class="cate-lv3-list">
       <!-- 三级分类的item项 -->
       <view class="cate-lv3-item" v-for="(item3,i3) in item2.children" :key='i3' @click="gotoGoodsList(item3)">
         <!-- 三级分类图片       -->
         <image :src="item3.cat_icon"></image>
         <text>{{item3.cat_name}}</text>
       </view>
     </view>
   </view>
 </scroll-view>
    </view>
  </view>
</template>

<script>
        import badgeMix from '@/mixins/tabbar-badge.js'
        
  export default {
     mixins: [badgeMix],
    data() {
      return {
        wh: 0,
        cateList: [],
        // 二级分类
        cateLevel2: [],
        // 当前选中项的索引，默认让第一项被选中
        active: 0,
          // 滚动条距离顶部的距离
            scrollTop: 0
      };
    },
    methods: {
      async getCateList() {
        // 发起请求
        const {
          data: res
        } = await uni.$http.get('/api/public/v1/categories')
        // 判断是否获取失败
        if (res.meta.status !== 200) return uni.$showMsg()
        // 转存数据
        console.log(res.message);
        this.cateList = res.message
        this.cateLevel2 = res.message[0].children
      },
      activeChanged(i) {
        this.active = i
        this.cateLevel2 = this.cateList[i].children
        this.scrollTop = this.scrollTop ? 0 : 1
      },  
      gotoGoodsList(item3){
        uni.navigateTo({
          url:'/subpkg/goods_list/goods_list?cid='+item3.cat_id
        })
      },  
      goSearch(){
     uni.navigateTo({
       url:'/subpkg/search/search'
     })
      }
    },
    onLoad() {
      const sysInfo = uni.getSystemInfoSync()
      // console.log(sysInfo);
      // 窗口的可用高度 =widowHeight= 屏幕高度 - navigationBar高度 - tabBar 高度
      this.wh = sysInfo.windowHeight-50
      this.getCateList()
    }
  }
</script>

<style lang="scss">
  .scroll-view-container {
    display: flex;

    .left-scroll-view {
      width: 120px;

      .left-scroll-view-item {
        line-height: 60px;
        background-color: #f7f7f7;
        text-align: center;
        font-size: 12px;

        // 激活项的样式
        &.active {
          background-color: #ffffff;
          position: relative;

          // 渲染激活项左侧的红色指示边线
          &::before {
            content: ' ';
            display: block;
            width: 3px;
            height: 30px;
            background-color: #c00000;
            position: absolute;
            left: 0;
            top: 50%;
            transform: translateY(-50%);
          }
        }
      }
    }
  }
  .cate-lv3-list {
    display: flex;
    flex-wrap: wrap;
  
    .cate-lv3-item {
      width: 33.33%;
      margin-bottom: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
  
      image {
        width: 60px;
        height: 60px;
      }
  
      text {
        font-size: 12px;
      }
    }
  }
  
</style>
